U.S. Provisional Application No. 61/216,521, filed May 18, 2009, is incorporated herein in its entirety by reference.
Presently, there is an increased demand for corn cobs as a feedstock for cellulosic ethanol, as well as other uses. As a result, there is heightened interest in collecting corn cobs during corn harvest. There is also concern by some that cob collection may reduce soil nutrient content. In this regard, crop residue or stover, e.g., corn stalks, leaves, husks and cobs, are traditionally left on the field after harvest, and break down over time to replenish soil nutrients. If a component of the stover, e.g., cobs is instead collected, nutrient levels could be lowered as a result. To mitigate this concern, some consider it desirable when collecting cobs, to collect only the cobs, with or without attached husks, and return the other residue or stover, referred to also as material other than cobs (MOC) to the field. Thus, it is sought to have a system for removing or cleaning MOC from cobs which can be adapted for operation in connection with a corn harvester, and which can be incorporated with a cob collection capability.
Numerous apparatus have been proposed for use in connection with cob collection devices, for cleaning or separating cobs from the other stover or MOC. To illustrate, prior to the early 1960's, the common corn harvesting practice involved picking the ears of corn in the field, removing husks from the ears, and transporting the ears still containing the corn kernels to a corn crib, and later shelling the corn off of the cobs at a stationary sheller. This harvesting procedure has been almost entirely replaced by modern self-propelled combine type harvesters, which separate and collect the corn kernels, and discharge the cobs and other stover onto the field.
Combines which harvest the corn and separate the kernels from the cobs and other stover or residue, then discharge the cobs and other stover onto the field, are now the industry standard. More recently, devices for collecting cobs discharged from combines have been developed. Several of such known devices have variously utilized a towed cart or wagon for receiving and holding the cobs, and a conveyor system for conveying the cobs from the combine to the cart or wagon. Some of the cob collection devices also include apparatus for separating the cobs from the other stover or MOC, mainly using air flow. Reference in this regard, Flamme U.S. Pat. No. 5,941,768, issued Aug. 24, 1999, which discloses a cob collection unit pulled behind a combine to collect on a first conveyor all the residue discharged from the combine, with a separation unit behind the conveyor including a second conveyor, and utilizing a fan to suck the stover from the cobs as they are released from the top of the second conveyor and to blow the stover back onto the field. Redekop et al. U.S. Patent Publication Nos. 20090095662 published Apr. 16, 2009; 20090104952 published Apr. 23, 2009; and 20090124309 published May 14, 2009, disclose a pulled cob collection unit, which utilizes a sequential series of inclined belt conveyors, and blower or suction fans for directing air upwardly through the discharged material as it falls from the upper end of one conveyor onto a lower end of the next conveyor, such that the heavier cobs are to continue to the next conveyor and the lighter stover or MOC will be carried upwardly by the air flow, with the cobs being conveyed into a collection tank by a further conveyor or conveyors, and the MOC to be directed by vanes sidewardly from the unit.
Reference also Stukenholtz U.S. Pat. No. 6,358,141 issued Mar. 19, 2002, and Redekop et al. U.S. Patent Publication No. 20090137295, which disclose cob collection systems on a combine which utilize on-board bins and cob separation using sieves on the combine itself.
A possible shortcoming of the above-discussed known cob cleaning devices and systems that direct air flows upwardly through falling cobs and MOC is that loose husks in the MOC, which are typically long and sinewy, can be retained by, and even wrapped around, the falling cobs, so as not to be cleaned or separated from the cobs. MOC contained in upwardly discharged air flows can also fall onto or into the adjacent cob collection device. And, when vanes or other apparatus are used for deflecting the MOC containing upward air flow sidewardly, they can become clogged if the air flow is not sufficiently strong or MOC is high in volume and/or moisture content. It is also difficult to distribute MOC over the swath of the cleaning device when the MOC is discharged upwardly or sidewardly.
Additionally, the above-listed known cob cleaning devices have only a limited or no ability to be configured differently for different conditions, such as the crop residue mixes of different corn varieties, e.g., percentage and/or size of MOC; harvester settings; yield; moisture content; and the like.
Thus, what is sought is a cob cleaning device or system, adaptable for operation in association with a harvester, and/or a cob collection device, which provides one or more of the capabilities, and overcomes one or more of the shortcomings, set forth above.